This application relates to computer-implemented vector illustration programs and methods and techniques for modifying vector objects using such programs and methods.
In conventional computer graphics or illustration programs, such as Adobe® Illustrator®, available from Adobe Systems Incorporated of San Jose, Calif., an image can include multiple graphical elements representing, e.g., shapes, objects or other components of the image. In general, vector illustration programs create and manipulate graphics in which such graphical elements are represented as vector objects that have attributes that define the visual characteristics of the corresponding graphical element in the image, such as location, color, size, shape, orientation, transparency, and the like, based on a set of attribute values. Vector objects describe graphics mathematically, using, e.g., lines and curves that define their geometric characteristics. For example, a bicycle tire in a vector graphic is made up of a mathematical definition of a circle drawn with a certain radius, set at a specific location, and filled with a specific color. Vector objects can be edited—e.g., the location, size, or color attributes can be changed—by changing attribute values associated with the object.
By contrast, many painting and image-editing programs, such as Adobe Photoshop, generate and manipulate bitmap or raster images. Raster images use a grid of pixels to represent graphics, with each pixel having a specific location and color value. A bicycle tire in a bitmap image is made up of a collection of pixels, with each pixel forming part of a mosaic that gives the appearance of a tire. A raster image is edited by editing pixels (i.e., by changing color or opacity values associated with a pixel), rather than objects or shapes.